FET transistor on a III-V material structure with substrate transfer
A method of manufacturing a III-V semiconductor circuit; the method comprising: forming a first layer of a III-V material on a growth substrate; forming a second layer of a III-V material on the first layer of III-V material; forming a FET transistor having a source electrode and a drain electrode in contact with a top surface of the second layer of a III-V material; forming a top dielectric layer above the FET transistor; forming a metal layer above the top dielectric layer, wherein said metal layer is connected to said source electrode; attaching a handle substrate to a top surface of the metal layer; removing the growth substrate from the bottom of the first layer of a III-V material; and forming a bottom dielectric layer on the bottom of the first layer of a III-V material.
1. A semiconductor circuit comprising a III-V material structure attached to a handle substrate by a metal bonding layer, wherein
the III-V material structure comprises:
a first layer of a III-V material, the first layer having a bottom surface and a top surface;
a second layer of a III-V material formed on the top surface of the first layer of a III-V material;
a first dielectric layer formed on the bottom surface of the first layer of a III-V material; and
a FET transistor having a source electrode and a drain electrode in contact with a top surface of the second layer of a III-V material; the FET transistor being covered by a second dielectric layer; and the second dielectric layer being covered by said metal bonding layer; and
wherein said metal bonding layer is connected to said source electrode; and wherein said metal bonding layer is connected to said source electrode by a plurality of vias.
2. The semiconductor circuit of claim 1 , wherein the III-V material is GaN.
3. The semiconductor circuit of claim 1 , wherein the drain electrode of the transistor is connected to a via that traverses at least the first and second layers of a III-V material.
4. The semiconductor circuit of claim 1 , wherein said metal bonding layer comprises a first sub-layer of metal deposited on top of the second dielectric layer and then planarized, and a second sub-layer of metal deposited on the bottom surface of the handle substrate; the first and second sub-layers of metal being bonded together.
5. The semiconductor circuit of claim 4 , wherein said metal bonding layer is gold.
6. The semiconductor circuit of claim 1 , comprising a barrier layer formed on the second layer of a III-V material, at least on a region located between the source and drain electrodes of the transistor.
7. The semiconductor circuit of claim 6 , wherein the barrier layer is an AlGaN layer.
8. The semiconductor circuit of claim 6 , wherein the transistor comprises a gate electrode formed above a gate dielectric layer formed above a portion of the barrier layer.
9. The semiconductor circuit of claim 8 , wherein the gate electrode of the transistor is connected to a via that traverses at least the first and second layers of a III-V material.